diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -864,6 +864,8 @@
 /// Determine whether this expression refers to a flexible array member in a
 /// struct. We disable array bounds checks for such members.
 static bool isFlexibleArrayMemberExpr(const Expr *E) {
+  // E->dump();
+
   // For compatibility with existing code, we treat arrays of length 0 or
   // 1 as flexible array members.
   // FIXME: This is inconsistent with the warning code in SemaChecking. Unify
@@ -877,8 +879,16 @@
   } else if (!isa<IncompleteArrayType>(AT))
     return false;
 
+  E->dump();
   E = E->IgnoreParens();
 
+  while (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
+    if (!BO->isCommaOp())
+      break;
+    E = BO->getRHS();
+    E = E->IgnoreParens();
+  }
+
   // A flexible array member must be the last member in the class.
   if (const auto *ME = dyn_cast<MemberExpr>(E)) {
     // FIXME: If the base type of the member expr is not FD->getParent(),
diff --git a/clang/test/CodeGen/bounds-checking.c b/clang/test/CodeGen/bounds-checking.c
--- a/clang/test/CodeGen/bounds-checking.c
+++ b/clang/test/CodeGen/bounds-checking.c
@@ -100,3 +100,19 @@
   return s->a[i];
   // CHECK: }
 }
+
+// CHECK-LABEL: define {{.*}} @SFlexComma
+int SFlexComma(struct SFlex *s, int i) {
+  // a and b are treated as flexible array members.
+  // CHECK-NOT: @llvm.trap
+  return (s->t, s->a)[i];
+  // CHECK: }
+}
+
+// CHECK-LABEL: define {{.*}} @S1Comma
+int S1Comma(struct S1 *s, int i) {
+  // a and b are treated as flexible array members.
+  // CHECK-NOT: @llvm.trap
+  return (s->t, s->a)[i];
+  // CHECK: }
+}
diff --git a/clang/test/CodeGen/bounds-checking.cpp b/clang/test/CodeGen/bounds-checking.cpp
--- a/clang/test/CodeGen/bounds-checking.cpp
+++ b/clang/test/CodeGen/bounds-checking.cpp
@@ -98,3 +98,19 @@
   return s->a[i];
   // CHECK: }
 }
+
+// CHECK-LABEL: define {{.*}} @_Z10SFlexComma
+int SFlexComma(struct SFlex *s, int i) {
+  // a and b are treated as flexible array members.
+  // CHECK-NOT: @llvm.trap
+  return (s->t, s->a)[i];
+  // CHECK: }
+}
+
+// CHECK-LABEL: define {{.*}} @_Z7S1Comma
+int S1Comma(struct S1 *s, int i) {
+  // a and b are treated as flexible array members.
+  // CHECK-NOT: @llvm.trap
+  return ((s->t, (1, s->a)))[i];
+  // CHECK: }
+}